This tool will return a list of candidate words: use the assign method for building
a complete UCD..
validate

Check if a UCD1+ is valid :

The first word of the result is an error code,
possibly followed by an explanation of the error.
This function will return 0 if the UCD1+ is fully valid.
The error-code results from the combination (logical OR) of the following values:

1: warning indicating use of non-standard namespace (not ivoa:)

2: use of deprecated word

4: use of non-existing word

16: syntax error (extra space or unallowed character)

Example: an error-code value of 10 will indicate the use of a deprecated word and a syntax error.
upgrade

The official UCD1+ words have sometimes undergone changes.
This function will upgrade deprecated words within a UCD1+ (causing
error-code 2 in validate) to their currently valid expression :